code: def __enter__(self):
      return self
  
imports: from __future__ import annotations
  import pytest
  from concurrent.futures import ThreadPoolExecutor
  from itertools import repeat
  from tornado.ioloop import IOLoop
  from bokeh.util.serialization import make_id
  from bokeh.util.tornado import _CallbackGroup
label_desc: Use image node_id 3 for calling the LoopAndGroup obj's underlying member method code with example usage: obj.__enter__() and returns: self